The present invention relates to a metal laminate gasket with a grommet, which can seal around a hole with different surface pressures.
In a gasket, a grommet has been used widely for sealing around a hole. The grommet operates to protect a gasket material around the hole from high heat, high pressure and so on. In a metal laminate gasket formed of a plurality of metal plates, the grommet may be used to prevent fluid from entering between the plates.
In the metal laminate gasket, a bead may also be formed on a plate around the hole to be sealed, which may be compressed by flanges of the grommet. This kind of gasket is disclosed in German Publication DE 3245383 A1, U.S. Pat. Nos. 4,714,260 and 4,898,3.96.
Further, in the metal laminate gasket, in case a pressure in a hole of the engine is high, several sealing devices are formed concentrically around the hole to thereby securely seal around the hole. In this case, the sealing devices may provide different surface pressures when the gasket is compressed, so that the portions around the hole can be sealed based on the characteristics of the engine parts.
For example, in case a portion around a cylinder bore is not strong, a sealing device near the cylinder bore does not provide high surface pressure when compressed, and instead, a sealing device away from the cylinder bore provides high surface pressure. The surface pressure of the sealing devices is controlled by changing thicknesses of the plates or the wire ring, strength of the bead and so on.
In the gasket with the grommet, the grommet has been used to cover the plates around the hole. Also, the bead may be situated between the flanges of the grommet and compressed to provide surface pressure thereat. However, there has not been proposed to provide different surface pressures at the grommet.
Accordingly, one object of the invention is to provide a metal laminate gasket with a main sealing section and an auxiliary or resilient sealing section, which is formed together with a grommet.
Another object of the invention is to provide a metal laminate gasket as stated above, wherein sealing ability is not affected by movement of the engine parts.
A further object of the invention is to provide a metal laminate gasket as stated above, wherein the surface pressures around the hole can be easily controlled.
A still further object of the invention is to provide a metal laminate gasket as stated above, which can be easily and economically manufactured.
Further objects of the invention will be apparent from the following description of the invention.